[arm fast-isel] Make the fast-isel implementation of memcpy respect alignment.
rdar://12821569
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169460 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMFastISel.cpp b/lib/Target/ARM/ARMFastISel.cpp
index 23d372c..21bb147 100644
--- a/lib/Target/ARM/ARMFastISel.cpp
+++ b/lib/Target/ARM/ARMFastISel.cpp
@@ -186,7 +186,8 @@
bool ARMComputeAddress(const Value *Obj, Address &Addr);
void ARMSimplifyAddress(Address &Addr, EVT VT, bool useAM3);
bool ARMIsMemCpySmall(uint64_t Len);
- bool ARMTryEmitSmallMemCpy(Address Dest, Address Src, uint64_t Len);
+ bool ARMTryEmitSmallMemCpy(Address Dest, Address Src, uint64_t Len,
+ unsigned Alignment);
unsigned ARMEmitIntExt(EVT SrcVT, unsigned SrcReg, EVT DestVT, bool isZExt);
unsigned ARMMaterializeFP(const ConstantFP *CFP, EVT VT);
unsigned ARMMaterializeInt(const Constant *C, EVT VT);
@@ -2422,21 +2423,30 @@
}
bool ARMFastISel::ARMTryEmitSmallMemCpy(Address Dest, Address Src,
- uint64_t Len) {
+ uint64_t Len, unsigned Alignment) {
// Make sure we don't bloat code by inlining very large memcpy's.
if (!ARMIsMemCpySmall(Len))
return false;
- // We don't care about alignment here since we just emit integer accesses.
while (Len) {
MVT VT;
- if (Len >= 4)
- VT = MVT::i32;
- else if (Len >= 2)
- VT = MVT::i16;
- else {
- assert(Len == 1);
- VT = MVT::i8;
+ if (!Alignment || Alignment >= 4) {
+ if (Len >= 4)
+ VT = MVT::i32;
+ else if (Len >= 2)
+ VT = MVT::i16;
+ else {
+ assert (Len == 1 && "Expected a length of 1!");
+ VT = MVT::i8;
+ }
+ } else {
+ // Bound based on alignment.
+ if (Len >= 2 && Alignment == 2)
+ VT = MVT::i16;
+ else {
+ assert (Alignment == 1 && "Expected an alignment of 1!");
+ VT = MVT::i8;
+ }
}
bool RV;
@@ -2515,7 +2525,8 @@
if (!ARMComputeAddress(MTI.getRawDest(), Dest) ||
!ARMComputeAddress(MTI.getRawSource(), Src))
return false;
- if (ARMTryEmitSmallMemCpy(Dest, Src, Len))
+ unsigned Alignment = MTI.getAlignment();
+ if (ARMTryEmitSmallMemCpy(Dest, Src, Len, Alignment))
return true;
}
}